Nearly four years after its controversial ruling in Citizens United v. Federal Election Commission, the Supreme Court is once again taking up the issue of the regulation of money in politics. This time, the risk to the integrity of elected officials, and public confidence in government, may be even greater.

On Tuesday, the court is scheduled to hear oral argument in McCutcheon v. Federal Election Commission, in which an Alabama businessman, Shaun McCutcheon, challenges the constitutionality of the overall cap on contributions an individual may make directly to federal candidates, party committees and political action committees in each two-year election cycle.

McCutcheon says this limit — currently set at $123,200 — violates his First Amendment right to free speech. The government argues that the overall limit, together with the $5,200 limit on an individual’s donations to a particular candidate, works to prevent political corruption, as well as the appearance of corruption.

The limits were enacted by Congress in the aftermath of the Watergate scandal. In a 1976 case, Buckley v. Valeo, the Supreme Court struck down limits on campaign spending, but upheld the limits on direct political contributions. Since then, the court has upheld every federal contribution limit that has come before it.

McCutcheon contends that striking down the overall limit would not undermine protections against corruption since an individual would still be bound by the per-candidate limits. But this ignores the reality of modern campaign finance, in which politicians and party committees solicit large sums from individual donors, and then funnel the money through fundraising committees to particular candidates. Without the current cap, the government argues, a single donor could give up to $3.6 million to a party’s political candidates and committees in an election cycle.

The very wealthiest Americans already have disproportionate influence: in the 2012 election, 1,219 donors reached or nearly reached the overall limit, and together they were responsible for giving $155 million to federal races. One study, by Demos and the U.S. Public Interest Research Group, projected that without the overall limit in place, those donors would have contributed nearly triple that amount — or 50 percent more than President Barack Obama and Mitt Romney received from all small donors combined. This is significant because a recent report by political science researchers showed that the wealthy differ significantly from ordinary Americans in their policy preferences. For example, job creation is consistently the top priority for most Americans, but among the wealthiest, the budget deficit is the most pressing problem.

Sensible contribution limits do not limit speech. As the court recognized in the Buckley case, they are a “quite modest restraint” that help prevent evasion of the per-candidate limit. An individual like McCutcheon may still say whatever he wants, and after Citizens United, he may spend all he would like on independent campaign-related messages.

The nation’s founders understood the threat of corruption in politics and were preoccupied with combating it. The government should be dependent on “the great body of the people,” James Madison wrote, and not “an inconsiderable proportion, or a favored class of it.” If the court is going to help protect American politics from becoming little more than “a disagreement among rich people,” as one observer put it, it should follow its own precedent and uphold the overall contribution limit.